Sökning: "Born-Oppenheimer theory"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Born-Oppenheimer theory.
1. Fingerprints of light-induced molecular transients : from quantum chemical models of ultrafast x-ray spectroscopy
Sammanfattning : Absorption of sunlight generates renewable electricity and powers the growth of plants, but also causes severe damage both to synthetic materials and biological tissue. The wildly varying outcomes of these light-induced processes are ultimately determined by much slighter differences in their underlying reaction pathways, induced by the transient properties of short-lived and miniscule molecules; a powerful approach to their detection and characterization is offered by ultrafast x-ray spectroscopy, with identification of spectral fingerprints and further guidance from quantum chemical models. LÄS MER
2. Complexity and Error Analysis of Numerical Methods for Wireless Channels, SDE, Random Variables and Quantum Mechanics
Sammanfattning : This thesis consists of the four papers which consider different aspects of stochastic process modeling, error analysis, and minimization of computational cost. In Paper I, we construct a Multipath Fading Channel (MFC) model for wireless channels with noise introduced through scatterers flipping on and off. LÄS MER
3. Non-linear Spectroscopy of Conical Intersections with XUV and X-ray Photons
Sammanfattning : Conical intersections (CIs) appear in a molecule due to the breakdown of the Born-Oppenheimer approximation when the energy difference between two or more electronic states decreases. CIs are known to play a crucial role in processes such as photosynthesis and vision in the human eye, and therefore it is important to probe the existence of such entities in molecules. LÄS MER
4. Density Functional Theory Studies of Small Supported Gold Clusters and Related Questions : What a Difference an Atom Makes
Sammanfattning : During the last decades the specific manipulation of matter on the (sub-) nanometer scale, also known as nanoscience, became possible by technologies such as the scanning tunneling microscope. Nanocatalysts, i.e. catalytic active structures of up to a few nanometers in size, belong to this rather new class of materials. LÄS MER
5. Ionization Influence on the Dynamics of Simple Organic Molecules
Sammanfattning : This licentiate thesis is devoted to the investigation of how bonding in simple organic molecules are affected by X-ray beam irradiation. The investigation targets molecules with three carbons as their main-chain structure. The stability of the bonds under ionization are simulated using the SIESTA package. LÄS MER
